English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

CommensalStreptococcus sanguinis andStreptococcus gordonii are pioneer oral biofilm colonizers. Characteristic for both is the SpxB-dependent production of H2 O2 , which is crucial for inhibiting competing biofilm members, especially the cariogenic speciesStreptococcus mutans . H2 O2 production is strongly affected by environmental conditions, but few mechanisms are known. Dental plaque pH is one of the key parameters dictating dental plaque ecology and ultimately oral health status. Therefore, the objective of the current study was to characterize the effects of environmental pH on H2 O2 production byS. sanguinis andS. gordonii .S. sanguinis H2 O2 production was not found to be affected by moderate changes in environmental pH, whereasS. gordonii H2 O2 production declined markedly in response to lower pH. Further investigation into the pyruvate node, the central metabolic switch modulating H2 O2 or lactic acid production, revealed increased lactic acid levels forS. gordonii at pH 6. The bias for lactic acid production at pH 6 resulted in concomitant improvement in the survival ofS. gordonii at low pH and seems to constitute part of the acid tolerance response ofS. gordonii . Differential responses to pH similarly affect other oral streptococcal species, suggesting that the observed results are part of a larger phenomenon linking environmental pH, central metabolism, and the capacity to produce antagonistic amounts of H2 O2 .IMPORTANCE Oral biofilms are subject to frequent and dramatic changes in pH.S. sanguinis andS. gordonii can compete with caries- and periodontitis-associated pathogens by generating H2 O2 . Therefore, it is crucial to understand howS. sanguinis andS. gordonii adapt to low pH and maintain their competitiveness under acid stress. The present study provides evidence that certain oral bacteria respond to environmental pH changes by tuning their metabolic output in favor of lactic acid production, to increase their acid survival, while others maintain their H2 O2 production at a constant level. The differential control of H2 O2 production provides important insights into the role of environmental conditions for growth competition of the oral flora.

Plasticity of the Pyruvate Node Modulates Hydrogen Peroxide Production and Acid Tolerance in Multiple Oral Streptococci